The 60 m Patrol Vessel has carried out repowering of the MTU 12V 956 TB 82 diesel engine with the power of 3000 kW replaced with an MTU 16V 595 TE 70L with the power of 4100kW. The air ventilation system currently installed has an average temperature of 330°K - 350°K, above the allowable temperature of the classification bureau of 318.15°K (450°C). The old air ventilation system has 2 blowers that suck outside air through 1 channel and branch into 2 channels to the engine room with 14 ventilation holes. Fluid dynamics computation using Numeca fine open software obtained an ideal air ventilation system design that requires 4 blowers with 2 different existing ducting forms, with the number of ducting outlets being 18. This design produces an average temperature of 303°K - 310°K, thus fulfilling the standard of the Indonesian Classification Bureau (BKI), which is a maximum of 318.15°K.